IRE1/XBP1s signaling: a novel essential regulator for bone marrow microenvironmen

IRE1/XBP1s 信号传导：骨髓微环境的新型重要调节因子

• 批准号: 9110217
• 负责人: Hongjiao Ouyang
• 金额: $ 38.56万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9110217
• 关键词: Animal Model; Applications Grants; Behavior; Binding Proteins; Binding Sites; Biological; Biology; Bone Diseases; Bone Growth; Bone Marrow; Bone Resorption; Boxing; CREB1 gene; Cells; Cellular Stress; Clinical; Degenerative polyarthritis; Disease model; Endoribonucleases; Factor X; Gene Expression; Generations; Genes; Genetic; Genetic Transcription; Goals; Growth; Healed; Health; Homeostasis; Human; Immunocompetent; In Vitro; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Interleukin-6; Knockout Mice; Leucine Zippers; Lytic Metastatic Lesion; MAPK14 gene; Maintenance; Malignant Neoplasms; Malignant neoplasm of lung; Malignant neoplasm of prostate; Marrow; Messenger RNA; Metastatic Neoplasm to the Bone; Modeling; Molecular; Morbidity - disease rate; Multiple Myeloma; Mus; Organ; Osteoclasts; Osteolysis; Patients; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Physiological; Play; Process; Production; Prognostic Marker; Protein Family; Protein Secretion; Proteins; RNA Splicing; Reporting; Role; Serine; Signal Transduction; Skeleton; Source; Stress; Stromal Cells; TNF gene; TNFSF11 gene; Testing; Therapeutic; Time; base; bone; cell growth; cell type; clinically significant; common cellular transcription factor ATF; craniofacial; cytokine; healing; in vivo; inhibitor/antagonist; insight; knock-down; malignant breast neoplasm; mouse model; neoplastic cell; novel; osteoclastogenesis; overexpression; prevent; promoter; protective effect; protein expression; response; therapeutic target; transcription factor; tumor; tumor growth

DESCRIPTION (provided by applicant): Multiple myeloma (MM) is the most frequent cancer to involve the skeleton and induces osteolytic lesions that rarely heal in both axial and craniofacial bones. Multiple myeloma bone disease (MMBD) is responsible for some of the most devastating complications of MM and is the major source of morbidity associated with MM. Bone marrow stromal cells (BMSC) are a major type of cells that reside within the MM microenvironment. It has been shown that in MMBD, BMSC produce many growth factors and inflammatory cytokines. These factors can boost the growth of the myeloma tumor cells and activate osteoclasts, the bone resorbing cells, to induce osteolytic lesions in bone. Thus, disrupting the BMSC support of MM cell growth and osteoclast formation is of major clinical significance in treating MMBD. Our long-term goal is to elucidate the molecular mechanisms that regulate BMSC support of MM cell growth and bone destruction in MMBD and identify the potential therapeutic targets for disrupting BMSC support of MMBD. Towards this goal, we have found that a cellular stress molecule spliced X-box-binding protein 1 (XBP1s) is induced in the BMSC derived from MM patients, compared with those from the healthy donors. XBP1s has been shown to control gene expression and/or protein secretion of inflammatory cytokines in other organs and disease models, such as inflammatory bowel disease. We showed recently that elevation of XBP1s protein levels in healthy donor BMSC induced the pathological behavior that are usually present in MM patient BMSCs, such as, heightened inflammatory cytokine secretion, enhanced support of MM cell growth and OCL formation both in vitro and in vivo. Conversely, knockdown of XBP1s in MM patient BMSC largely corrected their pathological behavior to the levels that are comparable to healthy donor BMSC. In this RO1 grant application, we hypothesize that IRE1α/XBP1s signaling is an essential pathophysiological factor that regulates the BMSC inflammatory signature and BMSC support of MM cell growth and osteoclastogenesis. Thus, the IRE1/XBP1s signaling in BMSC is a potential therapeutic target for disrupting BMSC support of MM cell growth and bone destruction in treating MMBD. The Specific Aims are: Aim 1: To determine the pathophysiological significance of p38-induced phosphorylation of human XBP1s (hXBP1s) in BMSC support of MM cell growth and osteoclastogenesis both in vitro and in vivo. Aim 2: To determine whether RANKL is a novel transcriptional target of XBP1s. Aim 3: To determine whether deletion of Xbp1 in BMSC blunts MM cell growth and bone resorption in vivo using a novel immunocompetent BMSC-specific Xbp1 KO mouse model. Aim 4: To determine if the IRE1α endoribonuclease activity in BMSC represents a potential therapeutic target to repress generation of XBP1s and disrupt BMSC support of MM cell growth and OCL formation. These studies have multiple biological, pathological and clinical implications. First, our studies will provide important information and related animal models for developing and employing therapeutic strategies that target the IRE1α/XBP1s signaling, such as the existing IRE1α inhibitors, and/or inflammation kinases-induced phosphorylation of XBP1s to disrupt the protective effects of the MM microenvironment on MM cells and OCL as a means to treat MMBD. Secondly, these studies will not only advance our understanding of basic biology of XBP1s but also provide important information on potential impact of an IRE1α/XBP1s inhibitor on bone microenvironment homeostasis of MM patients. Thirdly, since heightened stromal inflammatory cytokine secretion is a common pathological feature of many inflammatory bone diseases, such as rheumatoid osteoarthritis and tumor bone metastases (e.g., prostate, breast and lung cancers), our studies will provide important information and related animal models to investigate if the IRE1α/XBP1s signaling in BMSC is also a critical pathological factor in regulating the stromal cells support of progress of these inflammatory bone diseases, and thus represents a potential therapeutic targets for treating these inflammatory bone diseases.

描述(申请人提供)：多发性骨髓瘤(MM)是最常见的癌症，累及骨骼，并导致溶骨性损害，很少愈合在中枢骨和颅面部骨骼。多发性骨髓瘤骨病(MMBD)是多发性骨髓瘤(MM)最具破坏性的并发症，也是MM的主要发病率来源。骨髓基质细胞(BMSC)是MM微环境中的一种主要细胞类型。研究表明，在MMBD中，BMSC可产生多种生长因子和炎性细胞因子。这些因子可以促进骨髓瘤细胞的生长，并激活破骨细胞，骨吸收细胞，从而在骨中诱导溶骨性病变。因此，阻断骨髓间充质干细胞对MM细胞生长和破骨细胞形成的支持对治疗MMBD具有重要的临床意义。我们的长期目标是阐明MMBD中BMSC支持MM细胞生长和骨破坏的分子机制，并确定破坏BMSC对MMBD支持的潜在治疗靶点。为了达到这一目标，我们发现，与健康供者相比，多发性骨髓瘤患者的骨髓基质细胞中诱导了一种细胞应激分子剪接的X盒结合蛋白1(XBP1s)。XBP1已被证明在其他器官和疾病模型中控制炎性细胞因子的基因表达和/或蛋白质分泌，如炎症性肠病。我们最近发现，健康供者BMSC中XBP1s蛋白水平的升高导致了MM患者BMSCs常见的病理行为，如炎性细胞因子分泌增加，增强了对MM细胞生长的支持，以及体内和体外OCL的形成。相反，MM患者BMSC中XBP1基因的敲除在很大程度上纠正了他们的病理行为，达到了与健康供者BMSC相当的水平。在这项研究中，我们假设IRE1α/XBP1s信号是调节骨髓间充质干细胞炎症信号和骨髓间充质干细胞支持MM细胞生长和破骨分化的重要病理生理因子。因此，骨髓间充质干细胞中的IRE1/XBP1s信号转导通路是治疗多发性骨髓病的潜在靶点，可以阻断骨髓间充质干细胞对MM细胞生长和骨破坏的支持。具体目标是： 目的：探讨p38诱导的人XBP1s磷酸化(HXBP1s)在骨髓间充质干细胞(BMSC)体外和体内支持MM细胞生长和破骨分化中的病理生理学意义。 目的2：确定RANKL是否是XBP1s新的转录靶点。 目的：利用一种新的免疫活性的BMSC特异性XBP1 KO小鼠模型，研究BMSC中XBP1基因的缺失是否会抑制MM细胞的生长和体内的骨吸收。 目的：探讨骨髓间充质干细胞中IRE1α内切核酸酶活性是否可作为抑制XBP 1生成、阻断骨髓间充质干细胞对MM细胞生长和骨肉瘤形成的支持作用的潜在治疗靶点。 这些研究具有多方面的生物学、病理学和临床意义。首先，我们的研究将为开发和使用针对IRE1XBP1s信号的治疗策略提供重要的信息和相关的动物模型，例如现有的IRE1XBP1s抑制剂和/或炎症激酶诱导的XBP1s的磷酸化，以破坏MM微环境对MM细胞和OCL的保护作用，作为治疗MMBD的手段。其次，这些研究不仅将促进我们对XBP1s基础生物学的理解，还将为IRE1α/XBP1s抑制剂对MM患者骨微环境稳态的潜在影响提供重要信息。第三，由于间质炎性细胞因子分泌增加是许多炎症性骨疾病的共同病理特征，如类风湿性骨关节炎和肿瘤骨转移(如前列腺癌、乳腺癌和肺癌)，我们的研究将提供重要的信息和相关的动物模型，以探讨骨髓间充质干细胞中的IRE1α/XBP1S信号是否也是调节这些炎症性骨病进展的基质细胞支持进展的关键病理因素，从而成为治疗这些炎症性骨病的潜在治疗靶点。